Eh, lolis in manga and anime are usually a little sexualized, as the magical girl genre demonstrates. I've never been particularly bothered by it, since there's a disconnect between reality and illustration, at least to me. (Unless the age gap gets really intense, like 'Oshikku Sensei'. That's a little too messed up for me to dismiss.) Anyway, regardless of how sexy depictions of Fate Testarossa may or may not be, I'm comfortable in the knowledge that IRL kids don't appeal to me in the slightest.
That being said, in-universe-Mimika is totally a pedophile, and it's hilarious.